nfs_open.c

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/*
 * Copyright (C) 2013 Marin Hannache <ipxe@mareo.fr>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <libgen.h>
#include <byteswap.h>
#include <ipxe/time.h>
#include <ipxe/socket.h>
#include <ipxe/tcpip.h>
#include <ipxe/in.h>
#include <ipxe/iobuf.h>
#include <ipxe/xfer.h>
#include <ipxe/open.h>
#include <ipxe/uri.h>
#include <ipxe/features.h>
#include <ipxe/nfs.h>
#include <ipxe/nfs_open.h>
#include <ipxe/oncrpc.h>
#include <ipxe/oncrpc_iob.h>
#include <ipxe/portmap.h>
#include <ipxe/mount.h>
#include <ipxe/nfs_uri.h>

/** @file
 *
 * Network File System protocol
 *
 */

FEATURE ( FEATURE_PROTOCOL, "NFS", DHCP_EB_FEATURE_NFS, 1 );

#define NFS_RSIZE 100000

enum nfs_pm_state {
        NFS_PORTMAP_NONE = 0,
        NFS_PORTMAP_MOUNTPORT,
        NFS_PORTMAP_NFSPORT,
        MFS_PORTMAP_CLOSED,
};

enum nfs_mount_state {
        NFS_MOUNT_NONE = 0,
        NFS_MOUNT_MNT,
        NFS_MOUNT_UMNT,
        NFS_MOUNT_CLOSED,
};

enum nfs_state {
        NFS_NONE = 0,
        NFS_LOOKUP,
        NFS_LOOKUP_SENT,
        NFS_READLINK,
        NFS_READLINK_SENT,
        NFS_READ,
        NFS_READ_SENT,
        NFS_CLOSED,
};

/**
 * A NFS request
 *
 */
struct nfs_request {
        /** Reference counter */
        struct refcnt           refcnt;
        /** Data transfer interface */
        struct interface        xfer;

        struct interface        pm_intf;
        struct interface        mount_intf;
        struct interface        nfs_intf;

        enum nfs_pm_state       pm_state;
        enum nfs_mount_state    mount_state;
        enum nfs_state          nfs_state;

        struct oncrpc_session   pm_session;
        struct oncrpc_session   mount_session;
        struct oncrpc_session   nfs_session;

        struct oncrpc_cred_sys  auth_sys;

        char *                  hostname;
        struct nfs_uri          uri;

        struct nfs_fh           readlink_fh;
        struct nfs_fh           current_fh;
        uint64_t                file_offset;

        size_t                  remaining;
        int                     eof;
};

static void nfs_step ( struct nfs_request *nfs );

/**
 * Free NFS request
 *
 * @v refcnt            Reference counter
 */
static void nfs_free ( struct refcnt *refcnt ) {
        struct nfs_request      *nfs;

        nfs = container_of ( refcnt, struct nfs_request, refcnt );
        DBGC ( nfs, "NFS_OPEN %p freed\n", nfs );

        nfs_uri_free ( &nfs->uri );

        free ( nfs->hostname );
        free ( nfs->auth_sys.hostname );
        free ( nfs );
}

/**
 * Mark NFS operation as complete
 *
 * @v nfs               NFS request
 * @v rc                Return status code
 */
static void nfs_done ( struct nfs_request *nfs, int rc ) {
        if ( rc == 0 && nfs->nfs_state != NFS_CLOSED )
                rc = -ECONNRESET;

        DBGC ( nfs, "NFS_OPEN %p completed (%s)\n", nfs, strerror ( rc ) );

        intf_shutdown ( &nfs->xfer, rc );
        intf_shutdown ( &nfs->pm_intf, rc );
        intf_shutdown ( &nfs->mount_intf, rc );
        intf_shutdown ( &nfs->nfs_intf, rc );
}

static int nfs_connect ( struct interface *intf, uint16_t port,
                         const char *hostname ) {
        struct sockaddr_tcpip   peer;
        struct sockaddr_tcpip   local;

        if ( ! intf || ! hostname || ! port )
                return -EINVAL;

        memset ( &peer, 0, sizeof ( peer ) );
        memset ( &local, 0, sizeof ( local ) );
        peer.st_port = htons ( port );

        /* Use a local port < 1024 to avoid using the 'insecure' option in
         * /etc/exports file. */
        local.st_flags = TCPIP_BIND_PRIVILEGED;

        return xfer_open_named_socket ( intf, SOCK_STREAM,
                                        ( struct sockaddr * ) &peer, hostname,
                                        ( struct sockaddr * ) &local );
}

static void nfs_pm_step ( struct nfs_request *nfs ) {
        int     rc;

        if ( ! xfer_window ( &nfs->pm_intf ) )
                return;

        if ( nfs->pm_state == NFS_PORTMAP_NONE ) {
                DBGC ( nfs, "NFS_OPEN %p GETPORT call (mount)\n", nfs );

                rc = portmap_getport ( &nfs->pm_intf, &nfs->pm_session,
                                       ONCRPC_MOUNT, MOUNT_VERS,
                                       PORTMAP_PROTO_TCP );
                if ( rc != 0 )
                        goto err;

                nfs->pm_state++;
                return;
        }

        if ( nfs->pm_state == NFS_PORTMAP_NFSPORT ) {
                DBGC ( nfs, "NFS_OPEN %p GETPORT call (nfs)\n", nfs );

                rc = portmap_getport ( &nfs->pm_intf, &nfs->pm_session,
                                       ONCRPC_NFS, NFS_VERS,
                                       PORTMAP_PROTO_TCP );
                if ( rc != 0 )
                        goto err;

                return;
        }

        return;
err:
        nfs_done ( nfs, rc );
}

static int nfs_pm_deliver ( struct nfs_request *nfs,
                            struct io_buffer *io_buf,
                            struct xfer_metadata *meta __unused ) {
        int                             rc;
        struct oncrpc_reply             reply;
        struct portmap_getport_reply    getport_reply;

        oncrpc_get_reply ( &nfs->pm_session, &reply, io_buf );
        if ( reply.accept_state != 0 )
        {
                rc = -EPROTO;
                goto err;
        }

        if ( nfs->pm_state == NFS_PORTMAP_MOUNTPORT ) {
                DBGC ( nfs, "NFS_OPEN %p got GETPORT reply (mount)\n", nfs );

                rc = portmap_get_getport_reply ( &getport_reply, &reply );
                if ( rc != 0 )
                        goto err;

                rc = nfs_connect ( &nfs->mount_intf, getport_reply.port,
                                   nfs->hostname );
                if ( rc != 0 )
                        goto err;

                nfs->pm_state++;
                nfs_pm_step ( nfs );

                goto done;
        }

        if ( nfs->pm_state == NFS_PORTMAP_NFSPORT ) {
                DBGC ( nfs, "NFS_OPEN %p got GETPORT reply (nfs)\n", nfs );

                rc = portmap_get_getport_reply ( &getport_reply, &reply );
                if ( rc != 0 )
                        goto err;

                rc = nfs_connect ( &nfs->nfs_intf, getport_reply.port,
                                   nfs->hostname );
                if ( rc != 0 )
                        goto err;

                intf_shutdown ( &nfs->pm_intf, 0 );
                nfs->pm_state++;

                goto done;
        }

        rc = -EPROTO;
err:
        nfs_done ( nfs, rc );
done:
        free_iob ( io_buf );
        return 0;
}

static void nfs_mount_step ( struct nfs_request *nfs ) {
        int     rc;

        if ( ! xfer_window ( &nfs->mount_intf ) )
                return;

        if ( nfs->mount_state == NFS_MOUNT_NONE ) {
                DBGC ( nfs, "NFS_OPEN %p MNT call (%s)\n", nfs,
                       nfs_uri_mountpoint ( &nfs->uri ) );

                rc = mount_mnt ( &nfs->mount_intf, &nfs->mount_session,
                                 nfs_uri_mountpoint ( &nfs->uri ) );
                if ( rc != 0 )
                        goto err;

                nfs->mount_state++;
                return;
        }

        if ( nfs->mount_state == NFS_MOUNT_UMNT ) {
                DBGC ( nfs, "NFS_OPEN %p UMNT call\n", nfs );

                rc = mount_umnt ( &nfs->mount_intf, &nfs->mount_session,
                                 nfs_uri_mountpoint ( &nfs->uri ) );
                if ( rc != 0 )
                        goto err;
        }

        return;
err:
        nfs_done ( nfs, rc );
}

static int nfs_mount_deliver ( struct nfs_request *nfs,
                               struct io_buffer *io_buf,
                               struct xfer_metadata *meta __unused ) {
        int                     rc;
        struct oncrpc_reply     reply;
        struct mount_mnt_reply  mnt_reply;

        oncrpc_get_reply ( &nfs->mount_session, &reply, io_buf );
        if ( reply.accept_state != 0 )
        {
                rc = -EPROTO;
                goto err;
        }

        if ( nfs->mount_state == NFS_MOUNT_MNT ) {
                DBGC ( nfs, "NFS_OPEN %p got MNT reply\n", nfs );
                rc = mount_get_mnt_reply ( &mnt_reply, &reply );
                if ( rc != 0 ) {
                        switch ( mnt_reply.status ) {
                                case MNT3ERR_NOTDIR:
                                case MNT3ERR_NOENT:
                                case MNT3ERR_ACCES:
                                        break;

                                default:
                                        goto err;
                        }

                        if ( ! strcmp ( nfs_uri_mountpoint ( &nfs->uri ),
                                        "/" ) )
                                goto err;

                        if ( ( rc = nfs_uri_next_mountpoint ( &nfs->uri ) ) )
                                goto err;

                        DBGC ( nfs, "NFS_OPEN %p MNT failed retrying with " \
                               "%s\n", nfs, nfs_uri_mountpoint ( &nfs->uri ) );

                        nfs->mount_state--;
                        nfs_mount_step ( nfs );

                        goto done;
                }

                nfs->current_fh = mnt_reply.fh;
                nfs->nfs_state = NFS_LOOKUP;
                nfs_step ( nfs );

                goto done;
        }

        if ( nfs->mount_state == NFS_MOUNT_UMNT ) {
                DBGC ( nfs, "NFS_OPEN %p got UMNT reply\n", nfs );
                nfs_done ( nfs, 0 );

                goto done;
        }

        rc = -EPROTO;
err:
        nfs_done ( nfs, rc );
done:
        free_iob ( io_buf );
        return 0;
}

static void nfs_step ( struct nfs_request *nfs ) {
        int     rc;
        char    *path_component;

        if ( ! xfer_window ( &nfs->nfs_intf ) )
                return;

        if ( nfs->nfs_state == NFS_LOOKUP ) {
                path_component = nfs_uri_next_path_component ( &nfs->uri );

                DBGC ( nfs, "NFS_OPEN %p LOOKUP call (%s)\n", nfs,
                       path_component );

                rc = nfs_lookup ( &nfs->nfs_intf, &nfs->nfs_session,
                                  &nfs->current_fh, path_component );
                if ( rc != 0 )
                        goto err;

                nfs->nfs_state++;
                return;
        }


        if ( nfs->nfs_state == NFS_READLINK ) {
                DBGC ( nfs, "NFS_OPEN %p READLINK call\n", nfs );

                rc = nfs_readlink ( &nfs->nfs_intf, &nfs->nfs_session,
                                    &nfs->readlink_fh );
                if ( rc != 0 )
                        goto err;

                nfs->nfs_state++;
                return;
        }

        if ( nfs->nfs_state == NFS_READ ) {
                DBGC ( nfs, "NFS_OPEN %p READ call\n", nfs );

                rc = nfs_read ( &nfs->nfs_intf, &nfs->nfs_session,
                                &nfs->current_fh, nfs->file_offset,
                                NFS_RSIZE );
                if ( rc != 0 )
                        goto err;

                nfs->nfs_state++;
                return;
        }

        return;
err:
        nfs_done ( nfs, rc );
}

static int nfs_deliver ( struct nfs_request *nfs,
                         struct io_buffer *io_buf,
                         struct xfer_metadata *meta __unused ) {
        int                     rc;
        struct oncrpc_reply     reply;

        if ( nfs->remaining == 0 ) {
                oncrpc_get_reply ( &nfs->nfs_session, &reply, io_buf );
                if ( reply.accept_state != 0 ) {
                        rc = -EPROTO;
                        goto err;
                }
        }

        if ( nfs->nfs_state == NFS_LOOKUP_SENT ) {
                struct nfs_lookup_reply lookup_reply;

                DBGC ( nfs, "NFS_OPEN %p got LOOKUP reply\n", nfs );

                rc = nfs_get_lookup_reply ( &lookup_reply, &reply );
                if ( rc != 0 )
                        goto err;

                if ( lookup_reply.ent_type == NFS_ATTR_SYMLINK ) {
                        nfs->readlink_fh = lookup_reply.fh;
                        nfs->nfs_state   = NFS_READLINK;
                } else {
                        nfs->current_fh = lookup_reply.fh;

                        if ( nfs->uri.lookup_pos[0] == '\0' )
                                nfs->nfs_state = NFS_READ;
                        else
                                nfs->nfs_state--;
                }

                nfs_step ( nfs );
                goto done;
        }

        if ( nfs->nfs_state == NFS_READLINK_SENT ) {
                char                      *path;
                struct nfs_readlink_reply readlink_reply;

                DBGC ( nfs, "NFS_OPEN %p got READLINK reply\n", nfs );

                rc = nfs_get_readlink_reply ( &readlink_reply, &reply );
                if ( rc != 0 )
                        goto err;

                if ( readlink_reply.path_len == 0 )
                {
                        rc = -EINVAL;
                        goto err;
                }

                if ( ! ( path = strndup ( readlink_reply.path,
                                          readlink_reply.path_len ) ) )
                {
                        rc = -ENOMEM;
                        goto err;
                }

                nfs_uri_symlink ( &nfs->uri, path );
                free ( path );

                DBGC ( nfs, "NFS_OPEN %p new path: %s\n", nfs,
                       nfs->uri.path );

                nfs->nfs_state = NFS_LOOKUP;
                nfs_step ( nfs );
                goto done;
        }

        if ( nfs->nfs_state == NFS_READ_SENT ) {
                if ( nfs->remaining == 0 ) {
                        DBGC ( nfs, "NFS_OPEN %p got READ reply\n", nfs );

                        struct nfs_read_reply read_reply;

                        rc = nfs_get_read_reply ( &read_reply, &reply );
                        if ( rc != 0 )
                                goto err;

                        if ( nfs->file_offset == 0 ) {
                                DBGC2 ( nfs, "NFS_OPEN %p size: %llu bytes\n",
                                        nfs, read_reply.filesize );

                                xfer_seek ( &nfs->xfer, read_reply.filesize );
                                xfer_seek ( &nfs->xfer, 0 );
                        }

                        nfs->file_offset += read_reply.count;
                        nfs->remaining    = read_reply.count;
                        nfs->eof          = read_reply.eof;
                }

                size_t len = iob_len ( io_buf );
                if ( len > nfs->remaining )
                        iob_unput ( io_buf, len - nfs->remaining );

                nfs->remaining -= iob_len ( io_buf );

                DBGC ( nfs, "NFS_OPEN %p got %zd bytes\n", nfs,
                       iob_len ( io_buf ) );

                rc = xfer_deliver_iob ( &nfs->xfer, iob_disown ( io_buf ) );
                if ( rc != 0 )
                        goto err;

                if ( nfs->remaining == 0 ) {
                        if ( ! nfs->eof ) {
                                nfs->nfs_state--;
                                nfs_step ( nfs );
                        } else {
                                intf_shutdown ( &nfs->nfs_intf, 0 );
                                nfs->nfs_state++;
                                nfs->mount_state++;
                                nfs_mount_step ( nfs );
                        }
                }

                return 0;
        }

        rc = -EPROTO;
err:
        nfs_done ( nfs, rc );
done:
        free_iob ( io_buf );
        return 0;
}

/*****************************************************************************
 * Interfaces
 *
 */

static struct interface_operation nfs_xfer_operations[] = {
        INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
};

/** NFS data transfer interface descriptor */
static struct interface_descriptor nfs_xfer_desc =
        INTF_DESC ( struct nfs_request, xfer, nfs_xfer_operations );

static struct interface_operation nfs_pm_operations[] = {
        INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
        INTF_OP ( xfer_deliver, struct nfs_request *, nfs_pm_deliver ),
        INTF_OP ( xfer_window_changed, struct nfs_request *, nfs_pm_step ),
};

static struct interface_descriptor nfs_pm_desc =
        INTF_DESC ( struct nfs_request, pm_intf, nfs_pm_operations );

static struct interface_operation nfs_mount_operations[] = {
        INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
        INTF_OP ( xfer_deliver, struct nfs_request *, nfs_mount_deliver ),
        INTF_OP ( xfer_window_changed, struct nfs_request *, nfs_mount_step ),
};

static struct interface_descriptor nfs_mount_desc =
        INTF_DESC ( struct nfs_request, mount_intf, nfs_mount_operations );

static struct interface_operation nfs_operations[] = {
        INTF_OP ( intf_close, struct nfs_request *, nfs_done ),
        INTF_OP ( xfer_deliver, struct nfs_request *, nfs_deliver ),
        INTF_OP ( xfer_window_changed, struct nfs_request *, nfs_step ),
};

static struct interface_descriptor nfs_desc =
        INTF_DESC_PASSTHRU ( struct nfs_request, nfs_intf, nfs_operations,
                             xfer );

/*****************************************************************************
 *
 * URI opener
 *
 */

static int nfs_parse_uri ( struct nfs_request *nfs, const struct uri *uri ) {
        int     rc;

        if ( ! uri || ! uri->host || ! uri->path )
                return -EINVAL;

        if ( ( rc = nfs_uri_init ( &nfs->uri, uri ) ) != 0 )
                return rc;

        if ( ! ( nfs->hostname = strdup ( uri->host ) ) ) {
                rc = -ENOMEM;
                goto err_hostname;
        }

        DBGC ( nfs, "NFS_OPEN %p URI parsed: (mountpoint=%s, path=%s)\n",
               nfs, nfs_uri_mountpoint ( &nfs->uri), nfs->uri.path );

        return 0;

err_hostname:
        nfs_uri_free ( &nfs->uri );
        return rc;
}

/**
 * Initiate a NFS connection
 *
 * @v xfer              Data transfer interface
 * @v uri               Uniform Resource Identifier
 * @ret rc              Return status code
 */
static int nfs_open ( struct interface *xfer, struct uri *uri ) {
        int                     rc;
        struct nfs_request      *nfs;

        nfs = zalloc ( sizeof ( *nfs ) );
        if ( ! nfs )
                return -ENOMEM;

        rc = nfs_parse_uri( nfs, uri );
        if ( rc != 0 )
                goto err_uri;

        rc = oncrpc_init_cred_sys ( &nfs->auth_sys );
        if ( rc != 0 )
                goto err_cred;

        ref_init ( &nfs->refcnt, nfs_free );
        intf_init ( &nfs->xfer, &nfs_xfer_desc, &nfs->refcnt );
        intf_init ( &nfs->pm_intf, &nfs_pm_desc, &nfs->refcnt );
        intf_init ( &nfs->mount_intf, &nfs_mount_desc, &nfs->refcnt );
        intf_init ( &nfs->nfs_intf, &nfs_desc, &nfs->refcnt );

        portmap_init_session ( &nfs->pm_session, &nfs->auth_sys.credential );
        mount_init_session ( &nfs->mount_session, &nfs->auth_sys.credential );
        nfs_init_session ( &nfs->nfs_session, &nfs->auth_sys.credential );

        DBGC ( nfs, "NFS_OPEN %p connecting to port mapper (%s:%d)...\n", nfs,
               nfs->hostname, PORTMAP_PORT );

        rc = nfs_connect ( &nfs->pm_intf, PORTMAP_PORT, nfs->hostname );
        if ( rc != 0 )
                goto err_connect;

        /* Attach to parent interface, mortalise self, and return */
        intf_plug_plug ( &nfs->xfer, xfer );
        ref_put ( &nfs->refcnt );

        return 0;

err_connect:
        free ( nfs->auth_sys.hostname );
err_cred:
        nfs_uri_free ( &nfs->uri );
        free ( nfs->hostname );
err_uri:
        free ( nfs );
        return rc;
}

/** NFS URI opener */
struct uri_opener nfs_uri_opener __uri_opener = {
        .scheme = "nfs",
        .open   = nfs_open,
};